Surface treating appliances such as vacuum cleaners are well known. The majority of vacuum cleaners are either of the “upright” type or of the “cylinder” type (also referred to canister or barrel machines in some countries). An upright vacuum cleaner typically comprises a main body containing dirt and dust separating apparatus, a pair of wheels mounted on the main body for maneuvering the vacuum cleaner over a floor surface to be cleaned, and a cleaner head mounted on the main body. The cleaner head has a downwardly directed suction opening which faces the floor surface. The vacuum cleaner further comprises a motor-driven fan unit for drawing dirt-bearing air through the suction opening. The dirt-bearing air is conveyed to the separating apparatus so that dirt and dust can be separated from the air before the air is expelled to the atmosphere. The separating apparatus can take the form of a filter, a filter bag or, as is known, a cyclonic arrangement.
In use, a user reclines the main body of the vacuum cleaner towards the floor surface, and then sequentially pushes and pulls a handle which is attached to the main body of the cleaner to maneuver the vacuum cleaner over the floor surface. The dirt-bearing air flow drawn through the suction opening by the fan unit is conducted to the separating apparatus by a first air flow duct. When dirt and dust has been separated from the air flow, the air flow is conducted to a clean air outlet by a second air flow duct. One or more filters may be provided between the separating apparatus and the clean air outlet.
An example of an upright vacuum cleaner is described in WO2008/037955. The main body of the vacuum cleaner is moveable between an upright position and a reclined position for maneuvering over a floor surface to be cleaned. The vacuum cleaner comprises a stand which is moveable relative to the main body between a supporting position for supporting the main body in its upright position, and a retracted position so that the stand does not interfere with the maneuvering of the vacuum cleaner over the floor surface. The vacuum cleaner also comprises a hose and wand assembly connected to the main body through which air can be drawn into the vacuum cleaner and a changeover valve which is moveable to connect either the hose and wand assembly or the cleaner head to the fan unit depending on the position of the main body.
The changeover valve comprises a casing which houses a cylindrical drum. The casing comprises a first fluid inlet connected to the hose and wand assembly, a second fluid inlet connected to the cleaner head and a fluid outlet connected to the fan unit. The drum comprises a fluid inlet located on a side wall thereof, and a fluid outlet located on an end wall thereof. A wheel is connected to the drum to rotate the drum within the casing so that the fluid inlet of the drum is connected to a selected one of the fluid inlets of the casing. The wheel is rotated by the stand as the stand moves between its supporting and retracted positions. When the stand is in its supporting position the fluid inlet of the drum is connected to the hose and wand assembly, whereas when the stand is in its retracted position the fluid inlet of the drum is connected to the cleaner head.